Motorized lift truck



May 3, 1966 G. F. QUAYLE MOTORIZED LIFT TRUCK 5 Sheets-Sheet 1 FiledNov. 7, 1963 /17 g/Aa INVENTOR May 3, 1966 G. F. QUAYLE 3,249,170

MOTORI ZED LIFT TRUCK Filed Nov. 7, 1963 .'5 Sheets-Sheet 2 INVENTOR.GPSOQGE F 670A 'L6 BY M,

Tropf/5) May 3, 1966 G. F. QUAYLE MOTORIZED LIFT TRUCK 3 Sheets-Sheet 3Filed Nov. '7, 1963 INVENTOR. 660m@ F 00m/5 BY Arme/YD' United StatesPatent O Filed Nov. 7, 1963, Ser. No. 322,181 7 Claims. (Cl. 180-19)This invention relates to an industrial tru-ck, and more particularly,to an industrial truck having a motorized Ifront end drive.

Trucks of the particular class are very old in the art, and there arenumerous patents disclosing varying constructions. The concept that Ishall set forth in this application, and on 'which the truck of myinvention is based, relates to a particular construction :making itpossible to contribute a truck that is extremely simple in form, andwhich, therefore, lmakes possible the manufacture and sale of amotorized .truck at ra price that is very little more than ia truck ofthe particular class that is not motorized.

Thus, the truck that I have conceived utilizes an extremely simpleforward iframe construction that lends itself very rwell to lthemounting of the steering and traction unit, while -at the same timepermitting the assembly thereof to a load frame, and to lifting'mechanism extending bet-Ween the load frame and said forward frame. Inessence, the forward frame is formed as an inverted U and, preferably,is formed of simple bars or strips that are welded together to form thisinverted U. The base of the inverted U is readily adapted lfor themounting of the steering and traction unit, and may take the form of ahorizontal bar welded to the vstruts or legs forming the inverted U.Because of the bar construction of 'the legs of the inverted U, it ispossible to pivot upper and lower links to each of the bars at each sideof the inverted U, these legs extending to a conventional load liftingframe.

Further, the assembly of the legs to the inverted U- frame is.-facilitated by the upward extension of portions of the bars somewhatbeyond lthe 'horizontal connecting member or bar. Still further, it ispossible to extend from `this horizontal connecting member or bar ladepending member for the mounting of a ram that is positioned lbetweenthe depending member .and the load lifting frame for swinging the loadlifting frame on the links relatively to the forward frame.

It will thus be appreciated that through the utilization `of `a verysimple and functional U-frame, formed in a most economical manner by theuse of bar or strips, I can fabrica-te the essential forward end of amotorized truck in an extremely economical vmannenwmaking possible -thecontribution yof a motorized .truck at very slightly more thantheselling price of a simple hand lift truck. All of this will appear-rather clearly to those skilled in this art and who )are Iwell aware ofthe earlier constructions in this art, and who will understand thereforethe very considerable contribution that is made through my concepthereinafter set forth Iin detail.`

I have thus outlined rather broadly the more important features of myinvention in order that the detailed description thereof that followsmay be better understood, and in order that my contribution to the .artmay be better appreciated. There 4are, of course, additional features ofmy invention that Will be described hereinafter and which Iwill form thesubject of the claims `appended hereto. Those-skilled in the art willappreciate that the conception on which my disclosure is based 4mayreadily be utilized as a basis for the designing of other structures forcarrying out the several purposes of my invention. It isimportant,there-fore, that the claims be regarded as including `such equivalentconstructions .as do not depart from Ithe spirit and scope of myinvention, in order to prevent the appropriation of my invention by`those skilled in the art.

iF'IG. 1 is a side elevational View of a motorized hand lift truckconstructed in accordance with the invention;

FIG. 2 is a top plan view of the truck shown in FIG. l;

FIG. 3 is a sectional view taken on the line 33 of FIG. 1; and

FIG. 4 is an enlarged side elevational view,` partly in section, showingIthe load lifting elevating frame in raised position.

`Referring to the drawings, and in particular to FIGS. 1 and 2, there isshown a motorized hand lift truck T constructed in accordance with myinvention.

The tru-ck T includes a forward ina'in frame 10, a combined steeringland traction un'it =11 which is mounted for steering rotationrelatively to the main frame 10, and a load lifting or elevating frame.12. The load lifting frame 12 is supported at its forward end on themain frame 10 through laterally spaced pairs of upper and lower parallellinks 13 and '14 which extend between and are pivotally attached attheir `opposite ends to the load lifting frame |12 land the main frame10, respectively. The rear end of the load lifting frame 12 is supportedby roller 15 which pivot downwardly when the load lifting frame 112 iselevated. A hydraulic ram 16, extending between the forward end of theload lifting `frame `12 and the main frame E10, serves to elevate theforward end 0f the lo-ad lifting frame vlli?, relatively to the mainframe d0.

In accordance with the invention, the main frame 10 is in the lfform ofan inverted U, and in the preferred iform, as best shown in FIGSJ land4, the frame 10 is formed by a horizontal plate '17 and verticallyextending side bars or struts 18 which are welded, or otherwise secured,t-o the transversely opposed edges of the horizontal plate 17 anddiverge outwardly below the horizontal plate 17 to provide clearance forthe combined steering and traction unit 11.

The upper ends of the side Ibars or struts '18 extend a slight distancevabove the horizontal plate :17, and openings 19 are provided in theupper ends which receive pivots 20 by which the upper links 13 arepivotally attached to the main frame '10. The lower ends of the sidebars or struts 1S are Isimilarly provided with openings 21 which receivepivots 22 by which the lower links 14 are pivotally attached to the main'frame 110.

A crossplate 23 extends between the side bars or struts L18 and isfwelded, or otherwise secured, to the side bars or struts "18 and alsoto the horizontal plate 17. As best shown in IFIG. 4, an eye member 23ais welded to the center of the crossplate 23 .and receives a pivot 24 bywhich the lower end of the hydraulic ram -16 is pivoted to the mainframe 10.

As best sho-wn in FIG. 3, a hollow, cylindrical king post or bearing @5is welded to the crossplate A17 and extends downwardly through lthe-center of the crossplate 17. The portion of the king -post 25 whichextends below the crossplate 17 is received in upper yand Ilowerantifriction bearings 26 and 27 which are mounted in a hollow, upperextension 28 of the combined steering and traction unit 1/1. `The lowerend .29 of the king post 25 is threaded :and receives -a nut or suitableretainer 30 to prevent separation of the steering and traction unit y'11lfrom the king post 25, while allowing steering rotation of the steeringand .traction unit about the king post 25.

The steering and traction unit *11 is otherwise of conventionalconstruction and includes a traction wheel 3'1, an electric drive motor32 and Ia transmission, enclosed in a housing 3'3, through .which the.traction Wheel 31 is driven by the electric drive m-otor y32. As bestshown in FIG. 1, the combined steering and traction unit 1-1 is adaptedto be rotated about the `king post 25 to steer the traction 'Wheel -31`by means of an elongated steering .a handle 34 which is pivotallyattached at its lower end to the steeri-ng and traction unit \11 and isprovided with suitable switches 35 adjacent the upper end forcontrolling operation of the motor 32.

The load lifting or elevating frame i12 is of generally conventionalIconstruction .and includes channel shaped legs or forks -36 which aretransversely spaced to permit Itheir insertion into a pallet to belifted. The legs or forks 36 `are secured rtogether at their forwardends by a ver tically extended fra-me structure 37.

As `shown in FIG. 1, the upper links y13 Vare pivotally connected to thevertical `frame structure 37 of the load lifting frame 12 by 'means ofpivots 38, and the lower links 14 are secured to pivot shafts '39 whichare suitably journaled in the vertical frame structure 37 adjacent thelower end. A downwardly extending lever arm 40 is also secured 'to eachof the pivot shafts 39 .and each lever arm 40 is pivotally connected lbya pivot 41 to one end of an elongated connecting link 42 which extendsthrough each of the 'legs or forks l36. The opposite end of each of theelongated connecting links 42 is pivotally connected by means of .apivot 43 to a bell crank lever 44, which supports the roller d and whichis pivotally attached to the fork 36 by means of a pivot 45.

A suitable housing K46 mounted on the load lifting frame |12 adjacent.the vertical frame structure 37 enoloses batteries (not shown) forsupplying electrical energy for operating the electric drive motor 32.As shown in IFIG. 1 a multi-ple conductor cable 47 for transmittingelectrical energy from the batteries to .the 'electric drive 4motor 32,and also for providing control circuits for the Imotor, extends `fromthe housing 46 through the hollow king post 25 into the interior of thecombined steering and traction unit for connection with the motor 32 andthe switches 35 4on the handle. A simple hood 48, which is secured tothe vertical frame struct-ure 37, ex- .tends over the upper end of themain frame to protect and conceal the ram 16 and the condu-ctor 47. Anlelectric :motor driven pump (not shown) lfor supplying fluid underpressure for operating the ram 16 is mounted in the vertical framestructure 37 of the elevating frame v12.

When utilizing the ytruck to pick up a palletized load, the legs orfor-ks 316 are extended through the pallet while lifting frame l12 is inthe lowered position as shown in FIG. 1. -Fluid under* pressure is `thenadmitted to the hydraulic ram '16 to extend lthe -ram '1f6 and cause theforward end of the load lifting frame 12 to be elevated relatively tothe main frame 10. As the frame d2 `is elevated, lthe upper and lowerparallel supporting links -13 and 14 swing upwardly in a clockwisedirection, as viewed in FIG. 4, around their pivots 220 and 21. At thesame time, lthe lever 'arms '40, which are secured to the same pivotshafts 49 as the lower links 1'4, are rotated in a clockwise direction,thereby moving `the connecting rods 42 to lthe left, as viewed in FIG.4, causing the bell crank levers 44 to rotate in a counterclockwisedirection and move the supporting rollers i downwardly, as the forwardlend of the lifting frame 112 is elevated. The palletized load isthereby lifted a few inches from the ground vand may be transported byoperation of the truck through the drive motor 32.

F rom the preceding description it can be seen that there is provided avery simple, inexpensive, but yet rugged construction, for a .motorizedhand truck which permits a motorized hand Itruck to be manufactured andsold at a price that is only slightly more than a non-motorized handlift truck of conventional construction.

While one form of the invention has been shown and described, it will beappreciated that changes land modications may be made therein withoutdeparting from the spirit and scope of the invention.

I now claim:

`1. `In a lift truck, an inverted Uaframe, a ver-tical bearing securedlto an upper end portion of said inverted U- frame, a steering andtraction unit, means mounting said d'. steering and traction unit onsaid bearing `for supporting said U-frame while rotating relativelythereto for steering the truck and for movi-ng the truck, a load liftingframe, upper and lower parallel lin-ks pivoting the forward end of said'load lifting frame yt-o each leg of said Uframe, means mounted at apoint on said upper end portion o-f said U-frame and engaging the loadlifting frame for swinging said load lifting lframe Iin load liftingdirection on said` links relatively to said U-frame, load wheels underthe rear end of saidv load lifting frame, and mea-ns for moving saidload lifting wheels relatively to Isaid load lifting frame as `said loadlifting frame swings on said links rela-tively to said U-frame. l

2. In a lift truck, an inverted U-frame including a horizontal uppermember and .a pair of spaced downwardly extending legs, .a downwardlyextending vertical bearing secured to said horizontal upper memberbetween said legs, a steering and traction unit, means mounting saidsteering and traction unit on said bearing for supporting said U-framewhile rotating relatively thereto for steering the truck and for movingthe truck, a load lifting frame, upper `and lower parallel linkspivoting the forward end of said load lifting frame to each leg of saidU-frame, a hydraulic lift ram pivoted at one end to an upper end portionof said U-frame and at its other end to said load liftingy lframe andoperable for swinging said load lifting frame in load lifting directionon said links relatively to said U-frame, load wheels under the rear endof said load lifting frame, and means for moving said load liftingWheels relatively to said load lifting frame as said load lifting 4frameswings on said links relatively to said U-frame.

3. 'In a lift truck, aninverted U-frame comprising a pair of strutsextending downwardly from an upper horizontal connecting member, witheach of said struts having upper portions projecting slightly above saidconnecti-ng member, a downwardly projecting vertical bearing secured tosaid connecting member, a steering and tract-ion unit, means mountingsaid steering and traction unit on said bearing for supporting saidU-frarne while rotating relatively thereto for steering theftruck andfor moving the truck, a load lifting frame, upper and lower parallellinks pivoting the forward end of said load lifting frame for .liftingmovement on each strut of saidl U-frame with said upper links pivoted tothe said upper projecting portions of said struts, a depending membersecured to said horizontal connecting member and substantially alignedin a rearward direction relatively to the vertical bearing on |whichlthe steering and traction unit is mounted, a hydraulic lift ram pivotedto .a central portion of said load frame and to said depending memberand operable for swinging said l-oad lifting frame in load liftingdirection on said links relatively to said U-frame, load wheels underthe rear end of said load lifting frame, and means for moving said loadlifting wheels relatively to said load lifting frame as said loadlifting frame swings on said links. y

4. lIn Va lift truck, a steering and traction unit having a tractionwheel yand motor for driving the traction wheel, an inverted U-frameincluding a pair yof leg-s extending vertically in spaced relation toopposed sides of said steering and .traction unit, an .fupper portion ofsaid frame extending in position above the wheel and motor of saidsteering and traction unit between the `frame legs, a lift ram of thekind having two opposed ends that are movable relatively to each otherIby hydraulic pressure, means supporting one end of said rim at a pointon said upper portion of the U-frame, bearing means mounting thesteering and traction unit for steering rotation on said frame upperportion, a load lifting frame arranged rear- Iwardly of the Uaframe,upper and lower links pivoted between the forward end portion of theload lifting frame `and each leg of the U-frame, means Iwhereby theother end of the lift ram engages the forward end portion of the loadlifting frame for lifting that frame by swinging said links relativelyto the U-frame, load wheels operable to lift the rearward portion of theload lifting frame, and means operating said load wheels as the lift ramlifts the load lifting frame on .the links.

5. In a lift truck, a steering and traction unit having a tractionlwheel and motor for driving the traction wheel, 'an inverted Uframeincluding a pair of legs extending vertically in spaced relation ltoopposed sides of said steering and traction unit, an upper portion ofsaid frame extending in position above the wheel yand motor of saidsteering and traction unit between the iframe legs, lift Imeans havingone e-nd supported at Ia point on said upper portion of the U-frame,lbearing means mounting the steering and traction unit for steeringrotation on said frame upper portion, a load lifting vframe arrangedrearwardly of t-he U-frame, upper and lower links pivoted fbetween the:forward end portion of the load lifting frame and each leg of theU-frame, means whereby an opposed end of the lift means engages theforward end portion of 'the load lifting frame for lifting -that frameby swinging said links relatively to the U-frame, load wheels operable.to lift Ithe rearward portion of the load lifting frame, and meansoperating said load wheels as the lift means lift the load lifting frameon the links.

`6. In a lift truck, -a steering and traction unit having a tractionwheel and drive means for driving `the traction wheel, said drive meanslbeing relatively :wide so as to require considerable clearance duringsteering rotation of the steering and traction unit, an inverted U-frameincluding a pair of legs extending vertically in spaced relation toopposed sides of said steering and traction unit, an upper portion ofsaid frame extending in position above the wheel and drive means o-fsaid steering and traction unit between the frame legs and allowing theclearance necessary for said drive means, lift means mounted in upwardlyextending position .at a point on said .upper portion of the U-frame,bearing means mounting the steering and traction unit for steeringrotation on said Iframe upper portion, a load lifting frame arrangedrearwardly of the U-frame, upper `and lower links pivoted between theforward end portion of the load lifting frame and each leg of :theU-frame, means whereby the lift means engage the forward end vportion ofthe load lifting frame for lifting that Vframe `tby swinging said linksrelatively .to the Udrame, load wheels operable to lift the rearwardportion of the load lifting frame, and means operating said load wheelsas the lift means lift 4the load lifting frame on the links.

7. In a lift truck of the class having a forward frame, a steering andtraction unit mounted for steering rotation on the forward frame andincluding a traction wheel and a motor for driving said wheel, `arearward load lifting frame, pairs of links pi-voted between the frames,a hydraulic lift ram having opposed ends acting between the frames forlifting the rearward frame on the links relatively to the forward frame,yand load wheels lifting the rearward frame relatively to the ground asthat frame is lifted on the links, the improvement that comprises aninverted U-frame forming the forward frame of the truck, said U-frameincluding a pair of legs extending vertically in spaced relation toopposed sides of the steering and traction unit, each leg having pivotedto it one pair of said links, an upper portion of the U-frame extendingin position above the wheel and motor of t-he steering and traction unitbetween the legs of the U- frame, bearing means supporting .the`steering and tracti-on unit for `steering rotation on :said upper,portion of the U-frame, and ymeans supporting one end of said lift ramat a point on sa'id upper portion of the lU-frame that is substantiallyaligned in va rearward direction relatively to the bearing means onwhich the steering and traction unit is steered.

References Cited by the Examiner UNITED STATES PATENTS 2,325,396 7/1943Hastings 180--13 2,358,957 9/1944 Barrett 2SC-43.12 X 2,417,496 3/ 1947Framheinv 2542.6 2,538,680 1/1951 lFramhein 25A-2.6 2,598,151 5/1952Warshaw 2542.6 2,789,648 4/ 1957 Huffman M30-43.12 X

FOREIGN PATENTS 503,524 6/195-1 Belgium. 760,412 10/ 1956 `GreatBritain.

BENJAMIN HERSH, Primary Examiner.

C. C. PARSON, Assistant Examiner.

1. IN A LIFT TRUCK, AN INVERTED U-FRAME, A VERTICAL BEARING SECURED TOAN UPPER END PORTION OF SAID INVERTED UFRAME, A STEERING AND TRACTIONUNIT, MEANS MOUNTING SAID STEERING AND TRACTION UNIT ON SAID BEARING FORSUPPORTING SAID U-FRAME WHILE ROTATING RELATIVELY THERETO FOR STEERINGTHE TRUCK AND FOR MOVING THE TRUCK, A LOAD LIFTING FRAME, UPPER ANDLOWER PARALLEL LINKS PIVOTING THE FORWARD END OF SAID LOAD LIFTING FRAMETO EACH LEG OF SAID U-FRAME, MEANS MOUNTED AT A POINT ON SAID UPPER ENDPORTION OF SAID U-FRAME AND ENGAGING THE LOAD LIFTING